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The validity of a non-invasive blood lactate sensor




threshold, intensity domains, training, cycling, endurance


Blood lactate is routinely measured in endurance athletes to determine the physiological responses to exercise. The blood lactate profile allows the determination of thresholds that can be used to inform training and is often reported as the corresponding heart rate, speed, or power output. Wearable technology development has allowed blood lactate to be estimated in real-time rather than being restricted to laboratory-based testing during a single session. Following institutional ethical approval, eight male participants provided written informed consent to take part in this study. Each participant completed a lactate threshold testing protocol, starting at an intensity of 100 W, with 25 W increments observed every three minutes. At the end of each stage, a capillary blood lactate sample was taken (lab-based system). Throughout testing, it was anticipated that blood lactate could be estimated using bioimpedance spectroscopy (wearable sensor). There were two aspects of data analysis: firstly, to determine the predictive quality of blood lactate values from the wearable sensor, and secondly, to observe the agreement of lactate thresholds derived from the lab-based system and the wearable sensor values. Both wearable sensor and lab-based system blood lactate values were standardised within participants, with results demonstrating an exponential quadratic relationship. The greatest agreement in threshold detection was observed when using the ModDmax method with a bias of -0.95 [95% confidence interval: -13.85, 11.95] W. Further work is required to determine the baseline variation between participants and test the quadratic model.


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Poole DC (2009) Resolving the Determinants of High-Intensity Exercise Performance. Exp Physiol 94(2): 197–198.

Burnley M, Jones AM (2016) Power–Duration Relationship: Physiology, Fatigue, and the Limits of Human Performance. Eur J Sport Sci 18(1): 1–12.

Jones AM, Vanhatalo A, Burnley M, Morton RH, Poolce DC (2010) Critical Power: Implications for Determination of V̇O2max and Exercise Tolerance. Med Sci Sports Exerc 42(10): 1876–1890.

Ferguson BS, Rogatzki MJ, Goodwin ML, Kane DA, Rightmire Z, Gladden LB (2018) Lactate Metabolism: Historical Context, Prior Misinterpretations, and Current Understanding. Eur J Appl Physiol 118(4): 691–728. 10.1007/s00421-017-3795-6

Gaesser GA, Poole DC (1996) The Slow Component of Oxygen Uptake Kinetics in Humans. Exerc Sport Sci Rev 24(1): 35–70.

Davis JA, Rozenek R, DeCicco DM, Carizzi MT, Pham PH (2007) Comparison of Three Methods for Detection of The Lactate Threshold. Clin Physiol Funct Imaging 27(6): 381–384. 10.1111/j.1475-097X.2007.00762.x

Poole DC, Burnley M, Vanhatalo A, Rossiter HB, Jones AM (2016) Critical Power: An Important Fatigue Threshold in Exercise Physiology. Med Sci Sports Exerc 48(11): 2320.

Faude O, Kindermann W, Meyer T (2009) Lactate Threshold Concepts How Valid Are They? Sports Med 39(6): 469–490.

Eston R, Reilly T (2009) Kinanthropometry and Exercise Physiology Laboratory Manual: Tests, Procedures and Data. 3rd Ed. Routledge: UK.

Cheng B, Kuipers H, Snyder AC, Keizer HA, Jeukendrup A, Hesselink M (1992) A New Approach for The Determination of Ventilatory and Lactate Thresholds. Int J Sports Med, 13(7): 518–522.

Jamnick NA, Botella J, Pyne DB, Bishop DJ (2018) Manipulating Graded Exercise Test Variables Affects the Validity of the Lactate Threshold and VO2peak. PloS One, 13(7): E0199794.

Pyne DB, Boston T, Martin DT, Logan A (2000) Evaluation of the Lactate Pro Blood Lactate Analyser, Eur J App Physiol 82: 112–116.

Beneke R, Leithäuser RM, Ochentel O (2011) Blood lactate diagnostics in exercise testing and training. Int J Sports Physiol Perform 6(1): 8–24. 10.1123/ijspp.6.1.8

Driller M, Borges N, Plews D (2016) Evaluating A New Wearable Lactate Threshold Sensor in Recreational to Highly Trained Cyclists. Sports Eng 19(4): 229–235. 10.1007/s12283-016-0198-6

Borges NR, Driller MW (2016) Wearable lactate threshold predicting device is valid and reliable in runners. J Strength Cond Res 30(8): 2212–2218. 10.1519/JSC.0000000000001307

Parisi L, Alsup J, Benoit B, Patton D, Dimattia B (2022) A Comparison of Wearable Lactate Threshold Technology to Accepted Methods of Lactate Threshold Determination. J Ex Physiol Online 25(2): 1–6

Amrhein V, Trafimow D, Greenland S (2019) Inferential Statistics as Descriptive Statistics: There is no Replication Crisis if we Don’t Expect Replication. The Am Stat, 73(Sup1): 262–270.

Amrhein V, Greenland S, Mcshane B (2019) Scientists Rise Up Against Statistical Significance. Nature 567(7748): 305–307.

Sterba SK (2009) Alternative Model-Based and Design-Based Frameworks for Inference from Samples to Populations: From Polarization to Integration. Multi Beh Res 44(6): 711–740.

Cumming G (2014) The New Statistics: Why and How. Psych Sci 25(1): 7–29.

Wickham H, Chang W, Henry L, Pedersen TL, Takahashi K, Wilke C, Woo K, Yutani H, Dunnington D, Rstudio (2022) Ggplot2: Create Elegant Data Visualisations Using the Grammar of Graphics. https://Cran.R-Project.Org/Package=Ggplot2

Pedersen TL (2022) Patchwork: The Composer of Plots. https://Cran.R-Project.Org/Package=Patchwork

Bates D, Maechler M, Bolker B, Walker S, Christensen, RHB, Singmann H, Dai B, Scheipl F, Grothendieck G, Green P, Fox J, Bauer A, Krivitsky PN, Tanaka E. (2023) Lme4: Linear Mixed-Effects Models Using ’Eigen’ And S4. https://Cran.R-Project.Org/Web/Packages/Lme4/Index.Html

Bürkner PC. (2017) Brms: An R Package for Bayesian Multilevel Models Using Stan. Journal Of Statistical Software 80: 1–28.

Arel-Bundock V, Diniz MA, Greifer N (2022) Marginaleffects: Marginal Effects, Marginal Means, Predictions, And Contrasts. https://Cran.R-Project.Org/Package=Marginaleffects

Maturana FM (2023) Lactater: Tools for Analyzing Lactate Thresholds.

Caldwell A (2022) Simplyagree: Flexible and Robust Agreement and Reliability Analyses.


2024-03-14 — Updated on 2024-03-26